PORTLAND — This May, the American Red Cross is calling for donors to give blood and platelets regularly to be prepared to meet the needs of patients in emergency situations.

According to the National Trauma Institute, trauma accounts for approximately 41 million emergency department visits and 2 million hospital admissions each year.

In trauma situations, when there’s no time to check a patient’s blood type, emergency personnel reach for type O negative red blood cells and type AB plasma because they can be transfused to any patient, regardless of blood type. Less than 7 percent of the population has type O negative blood, and only about 4 percent of the population has type AB blood.

Platelets may also be needed to help with clotting in cases of massive bleeding. Because platelets must be transfused within five days of donation, there is a constant — often critical — need to keep up with hospital demand.

Donors of all blood types are urged to roll up a sleeve this May to help meet the needs of trauma patients and others with serious medical conditions. Make an appointment to donate blood by downloading the free Red Cross Blood Donor App, visiting RedCrossBlood.org or calling 1-800-RED CROSS (1-800-733-2767).

All those who donate through May 13 will be entered to win one of three $1,000 gift cards to a national home improvement retailer.

Upcoming local blood donation opportunities include:

Auburn: 9 a.m. to 2 p.m. Saturday, May 12, at Grace Lutheran Church, 757 Summer St.

Bethel: Noon to 5 p.m. Tuesday, May 1, at Telstar High School, 284 Walkers Mills Road, Route 2.

Buckfield: Noon to 5 p.m. Monday, May 2, at Buckfield High School, 160 Morrill St.

Casco: 2 to 7 p.m. Wednesday, May 9, at Casco Village Church, 941 Meadow Road.

Farmington: 11 a.m. to 4 p.m. Tuesday, May 8, at Mount Blue High School, 129 Seamon Road.

Fryeburg: Noon to 5 p.m. Tuesday, May 1, at Gibson Recreation Center at Fryeburg Academy, 745 Main St.; and from 9 a.m. to 2 p.m. Saturday, May 5, at Masons Pythagorean Lodge No. 11, 50 Portland St.

Gray: 10 a.m. to 4 p.m. Saturday, May 26, at the Maine Wildlife Park, 56 Game Farm Road.

Hiram: 8:30 a.m. to 2:30 p.m. Tuesday, May 1, at Sacopee Valley High School, 115 South Hiram Road.

Lewiston: 3 to 8 p.m. Tuesday, May 8, at Bates College, 56 Campus Ave.; and Central Maine Medical Center Blood Donation Center, 60 High St. Visit tinyurl.com/yd7522ll to schedule with this center or call 1-800-RED CROSS.

New Gloucester: 2 to 7 p.m. Monday, May 14, at Memorial School, 86 Intervale Road; and from 9 a.m. to 2 p.m. Wednesday, May 23, at Pineland Farms, 59 Pineland Drive.

Poland: 9 a.m. to 2 p.m. Saturday, May 5 at the Poland Town Hall, 1223 Maine St., Route 26.

Porter: 1 to 6 p.m. Monday, May 21, at Riverside United Methodist Church, 5 School St.

Strong: 2 to 6 p.m. Friday, May 25, at Forster Memorial Building, 11 Main St.

Turner: 7:45 a.m. to 1 p.m. Thursday, May 3, at Leavitt Area High School, 21 Matthews Way.

Topsham: 1 to 6 p.m. Monday, May 7, at ARC Mid Coast Chapter, 16 Community Way; and from 10 a.m. to 3 p.m. Monday, May 21, at Servpro Topsham, 28 Monument Place, Suite D.